TPS is reading 1% at idle, and the oem new O2 (4wire) sensor reading is 3.85volts. The secondary O2 sensor is bypassed. I'll be measuring the voltage of the TPS tonight to see if it needs adjusted or is faulty, but was wondering if there were any ideas as to what else the problem could be. Running Hondata s300. Replaced coil and ignitor with spares just for good measure. Also get roaming during warm up, but not at operating temp. However, at operating temp i will occasionally get a cut in the power at a consistent throttle position. The rpm's will drop a few hundred and then power back up.

Any ideas other than checking TPS voltage are appreciated!

J

 

To follow up: the tps was reading .6 so it was adjusted back to .45. it then showed 4.38 at wot. maybe a dead spot in the base map. will see what happens after it goes in for tuning.

 

.5-4.5v ~ is what i look for give or take a litte, o2 reading 3.85v? thats pretty ****ing high .1-.9v~ is the normal range for a narrowband right? 3.85v tells me there is alot of oxygen reacting with the sensor, major exhaust leak?

 

thanks for the input! i knew that was a high # on the o2 sensor, so i'm gonna continue looking for the issue. I haven't been able to find a leak, but it would seem to me that maybe the header is leaking somewhere... maybe the o2 sensor needs tightened in the bung?

 

i found a loose connection between the catback and one of the resonators. could this be the problem? i would think that the high voltage would indicate an issue infront of the o2 sensor instead of behind it. am i wrong thinking this?

 

no you're right. is it a two piece header?

 

no. it's a one piece comptech. header nuts are checked and at spec torque. i have no pcv valve in place, but have the assembly ordered. I do not think that this is the cause though because it was set up like this prior and ran with no issues and i was told by the tuner that it would not cause significant issues other than crap being blown on the engine. iacv is bypassed, yet the nipples are not blocked off yet. they will be tomorrow. fitv is bypassed with hose connecting one side to the other. i'll be checking for other vacuum leaks tomorrow with the light. the warm up roaming idle is not a concern so much as the power cutting out while driving at operating temp then thumping back in. not good when pulling away from stop signs and red lights! thanks again for the help guys!

I'm still thinking that just putting it on the dyno and having it tuned will be the best bet. Jan 15th! Can't wait for that...

 

3.85v O2 reading means you have an open in the wire between the O2 and ECU.

 

sounds like i have a weekend date with the voltmeter... is it best to start with the signal wire or power wire? thanks for the reply, it's really appreciated.

 

First, I'd like to thank everyone for the help. Secondly, I found the issue, and of course it was something stupid and simple.

When the tuner put my engine in, the plugs for the primary and secondary o2 sensor were switched, so the ECU was seeing the secondary, by-passed o2 sensor as the primary. Thank God for service manuals. I noticed the wire color combination was switched, so I reversed the plugs and monitered the s300 sensor tables as the V droped from 3.85 down to .1 volts.

the victory beer never tasted so good!

Thanks guys!